This invention relates to the delivery as a fine mist of dental treatment compositions having viscosities capable of responding to a change in temperature. The invention also relates to devices for applying the compositions as a fine mist.
In the dental art, the use of a dental treatment composition is generally desirable for numerous applications or indications including, for example, treatment of caries, calculus build-up, xerostomia, stained dentition, bad breath, gingivitis, bacterial infections, oral pain or sensitivity such as sore throat, canker sores, and burns. To attain proper application and effectiveness at the desired location, it is desirable that the composition be controllable and slow to flow away from it target site. Thus a high viscosity dental composition in the oral environment would be quite useful.
Currently available dental compositions are provided in seemingly extreme viscosity states. That is, there exist compositions that have very low viscosities as well as compositions that are highly thickened and therefore possess high viscosity. Those with low viscosities are difficult to control and have tendencies to flow away from the target site once it is applied. Compositions with high viscosities are difficult to extrude through a small orifice.
Certain dental compositions may use thickeners such as fumed silica and/or polymer additives such as polyvinyl alcohols, polyethylene glycols, and the like. Problems encountered in using these thickeners include aging, which results in non-homogenous gels which make handling difficult, and shear thinning, which reduces the viscosity of a gel when extruded through an orifice and thinning at elevated temperatures. Thinning can result in a material that drips from the desired point of application.
Dental etching compositions, which are suitable for etching hard tissue and include an acid and a thermally responsive viscosity modifier, are disclosed in PCT International Publication No. WO 00/28946. Dental whitening compositions that include a whitening agent and a thermally responsive viscosity modifier are disclosed in PCT International Publication No. WO 00/28955. Such compositions are capable of being applied to a target site through an orifice (e.g., a syringe), whereupon they undergo an increase in viscosity in response to an increase in temperature. The increase in viscosity is useful in preventing the dental compositions from flowing away from the target area of application.
There exists a need in the art for convenient methods of delivering dental compositions to target sites, and for the compositions to remain at the target application area after delivery.
In one aspect, the present invention provides a method of applying a dental composition in the oral environment using an aqueous dental composition including about 10% by weight to about 50% by weight of a thermally responsive viscosity modifier and water, wherein the composition is in a low viscosity state at a pre-treatment temperature and a highly viscous state at a treatment temperature that is higher than the pre-treatment temperature. The method includes spraying the composition as a fine mist onto a surface, wherein the composition is at the pretreatment temperature and in the low viscosity state prior to being sprayed onto the surface, allowing the composition to warm to the treatment temperature and increase in viscosity to the highly viscous state wherein the viscosity of the composition at the treatment temperature is at least about 10 times the viscosity of the composition at the pre-treatment temperature, and allowing the composition to remain on the surface. Preferably the pre-treatment temperature at most about room temperature and the treatment temperature is about body temperature. The dental composition may optionally include adjuvants such as acids, whitening agents, fluoride sources, stability promotors, anti-microbial agents, anti-fungal agents, anti-calculus forming agents, preservatives, adhesive modifiers, fillers, dyes, detection indicators (e.g., for caries, gingivitis, and the like), cariostatic agents, flavorings, sweeteners, medicaments, sodium bicarbonate, specific enzymes, hydrating agents, and breath fresheners. The dental composition optionally may also include a propellant.
In another aspect, the present invention provides a spray device including a container; an aqueous dental composition in the container, the composition including about 10% by weight to about 50% by weight of a thermally responsive viscosity modifier and water, wherein the composition is in a low viscosity state at a pre-treatment temperature and a highly viscous state at a treatment temperature that is higher than the pre-treatment temperature; and a sprayer in fluid communication with the dental composition, the device being capable of spraying the dental composition as a fine mist into the oral environment. Optionally, the device may further include a propellant.
In another aspect, the present invention provides a fine mist of a dental composition in the oral environment, the composition including about 10% by weight to about 50% by weight of a thermally responsive viscosity modifier and water, wherein the composition is in a low viscosity state at a pre-treatment temperature and a highly viscous state at a treatment temperature that is higher than the pre-treatment temperature.
In another aspect, the present invention provides a dental composition capable of being sprayed as a fine mist into the oral environment, the composition including about 10% by weight to about 50% by weight of a thermally responsive viscosity modifier; water; and a propellant, wherein the composition is in a low viscosity state at a pre-treatment temperature and a highly viscous state at a treatment temperature that is higher than the pre-treatment temperature.